Passengers on a busy Tube line face more than 18 months of periodic part-closures - because acidic water is eating away at the tunnel walls.
London Underground's Jubilee line will shut for over a month during the next two years because acidic water is eating into the cast iron linings of the tunnel walls.
The work includes six-day closures between Finchley Road and Waterloo stations during Christmas this year and next, as well as over the Easter period in 2014.
Services will be halted in both directions between Finchley Road and Waterloo for major repairs which will cost £40¿million
The acidic water is similar in strength to vinegar and comes from water seeping in from surrounding soil.
Services will be halted in both directions between Finchley Road and Waterloo for major repairs which will cost £40 million, the Evening Standard reported.
The work covers a number of weekends and bank holiday periods from June this year to the end of 2014, with the possibility of some additional closures in 2015 in order to complete the maintenance.
Engineers are concerned about the state of more than 90 yards of the southbound tunnel between Baker Street and Bond Street.
Sections of the tunnel will have to be replaced as part of the extensive work.
The acidic water is similar in strength to vinegar and comes from water seeping in from surrounding soil
London Underground’s Jubilee, Northern and Piccadilly lines’ programme director Stuart Harvey said today: 'All railways require a programme of maintenance and we will soon be carrying out work on the tunnel lining on a section of the Jubilee line.
'This is part of ongoing maintenance and, due to the nature of the work, some closures during weekends will unfortunately be required between Finchley Road and Waterloo.'
He went on: 'We will be doing as much of the work as possible overnight; however, in some cases we need to carry on beyond normal overnight engineering hours and normal weekend services will not be able to operate.
'I apologise to customers for the disruption. We’ll be keeping the impact to a minimum by spreading the work out and including some later-starting services on Sunday mornings to minimise the overall number of closures.'
The Jubilee line is the Underground's newest line, but serves stations which originally opened over 100 years ago.
Inaugurated on 1 May 1979, the Jubilee line linked up the most recent sections of new tunnelling to open in central London - the four km (2.5 miles) of twin tunnels between Baker Street and Charing Cross - with the former Bakerloo line branch between Baker Street and Stanmore.
The northern end of the line between Wembley Park and Stanmore was opened in 1932 as a branch of the then Metropolitan Railway.